This should ensure that tests are NOT packaged into
release package by setuptools, as tests are development
only
+ fixtures after moving

Signed-off-by: Konrad Weihmann <kweihmann@outlook.com>

Also change TestActor to subclass TestBase rather than object and create and use base TestCommitSerialization class for assert_commit_serialization method

That way, we will try to decode as default encoding (usually
utf-8), but allow ourselves to simply keep bytes that don't
match within the resulting unicode string.

That way, we allow for lossless decode/encode cycles while still
assuring that decoding never fails.

NOTE: I was too lazy to create a test that would verify it, but manually
executed https://github.com/petertodd/gitpython-unicode-error.

fixes #532

+ Fixed the hangs at `test_git:TestGit.test_handle_process_output()`.
[travisci skip]

Previously timezones which were not divisable by 3600s would be
parsed correctly, but would serialize into a full hour, rounded up.

Now floating point computation is used which fixes the issue.

Related to #336

Now it's about going through PY3 issues

However, StringIO really is ByteIO in most cases, and py2.7 should
run but doesn't.
This should be made work first.